The invention relates to load indicators for indicating tensile stresses on traction elements, for example lashing belts or lashing cables. For the sake of simplicity, these traction elements are referred to hereinafter as xe2x80x9cbeltsxe2x80x9d or xe2x80x9cbelt.xe2x80x9d They are provided with a loop or eyelet for securing an adaptation part that introduces a counter-holding force to the traction element. The adaptation part can be, for example, the stud of a shackle or the stop pin of a bracing ratchet.
In lashing or bracing elements, a load indicator of this type serves to indicate visually to the user which load is present, and particularly whether a hazardous situation must be remedied. During the transport of lashed loads, for example on trucks, the load shifts from time to time due to external forces. This shifting often causes severe stress to the lashing element, which can pose a threat to the operator when the load is removed. Conventionally, load indicators are mounted with ratchet spanners; these indicators preferably serve to indicate the prestress force during lashing, but can also give a warning indication of a stress of the lashing that has occurred due to load shifting. Because of their complicated design, these load indicators are relatively costly.
GB 2 255 109 A discloses a load indicator that has the features of the preamble to claim 1. In this device, which is specified for cables, the indicator body is formed by a cable eye stiffener that has been modified for this purpose. In a simple version of this load indicator, the cable eye stiffener, which is closed all the way around, is provided in the region of its ring shape that faces the tip of the teardrop shape of the loop, and is no longer acted upon by the inside flanks of the loop, with a radial slit that allows the stiffener legs that rest against the inside flanks of the loop some play in the direction toward one another. This small amount of play gives the legs of the stiffener, which is relatively rigid due to its house-shaped cross section, an elastic mobility in the direction toward one another in a high-stress region. A mechanical indicator makes the magnitude of this movement recognizable, and consequently. permits conclusions about the load status. This load indicator is only suited for indicating high-load statuses. It is relatively imprecise and, furthermore, fairly structurally complex.
A load indicator known from GB 2 223 102 A, which only functions similarly to the aforementioned indicator, has a specially-shaped molded body that surrounds the traction pin over 360xc2x0 between the loop of the traction element and the stud of a shackle that extends into the loop, the molded body being deformable under a load. The degree of deformation that occurs under a load is used in the manner of an expansion-measuring device as an indicator for the present load.
In contrast, it is the object of the invention to embody a load indicator of the type defined in the preamble to claim 1 such that it even indicates low load forces, and is therefore effective over the entire load range of the traction element. Moreover, it is intended to be manufactured inexpensively and reliably indicate dangerous tensile-force situations. This solution is based on the deformation that only the loop or eyelet, which has widened slightly under zero load, experiences under a load due to the increasing approximation of the teardrop cross-section shape, and its expansion. These belt loops or belt eyelets have an approximately teardrop-shaped outline, with the tip of the drop pointing in the belt direction under a load, when the adaptation part extending into the belt eyelet introduces the counterforce. Usually, belt eyelets or belt loops are formed in that the belt generally representing the term xe2x80x9ctraction elementxe2x80x9d is shifted at one end by 180 degrees and, in this relocated position, the belt end is fixed directly on the belt, or, in the case of a cable as the traction element, is spliced with the cable. As the tensile stress increases, the teardrop shape becomes more distinctly formed, because the inside flanks of the belt loop or belt eyelet approach one another. The degree of this approach is visually more easily recognizable due to the load indicator than in the case of mere inspection of the belt loop or belt eyelet. One embodiment characterizes an especially simple embodiment of the load indicator. In a different embodiment, the ends of the indicator body are not in direct contact with the belt. Another emobodiment improves the recognition of the distance between the legs. Another variation makes it possible to identify intermediate loads between no load and a hazardous load. This makes different load levels more clearly recognizable.